A Delta Air Lines flight en-route to Beijing from Seattle returned back on Thursday night for security reasons. As per the information from CNN, an unruly passenger tried to enter the jet’s cockpit and the plane turned back following the passenger’s attack on a flight attendant in the first class cabin.

According to the spokesperson of Seattle Airport, “Three people; one passenger, one flight attendant and the unruly passenger got injured in the incident. The flight turned back as it was flying over the western coast of Canada.”

The Delta flight 129 with the Boeing 767 returned safely at Seattle-Tacoma International Airport around 7:40 p.m. local time under a Department of Defense escort. Law enforcement officers took the passenger into custody after the flight returned to the gate, Delta said. The new flight departed few minutes after midnight.

A source from FBI said, “The FBI’s investigation is ongoing and more details about the incident will be provided and the charges announced at the subject’s initial appearance in federal court.”